Smart cities are taking off globally, with about a quarter of all current implementations in the Asia-Pacific region, according to a new report which also forecasted that spending on smart city technologies will grow significantly over the next five years.

In a Friday statement, ABI Research reported that there are currently 102 smart city projects running worldwide. With 21 initiatives, the Asia-Pacific region is ranked third behind Europe and North America, which have 38 and 35 projects, respectively.

According to the research firm, a smart city is defined by six dimensions: smart economy, environment, governance, lifestyle, transportation and community.

Spending on smart city technologies is expected to grow, ABI Research said in its report. Last year, US$8.1 billion was spent to build smart cities, and this expenditure will grow to reach US$39.5 billion by 2016.

"Smart city concepts are really taking off globally," said Josh Flood, senior analyst at ABI Research, in the statement. Currently, smart grids account for the bulk of spending on smart city technologies, but Flood predicted "significant increase" in investments on smart transportation technologies such as automatic vehicle identification as well as smart governance systems such as e-ID and identity document systems.

In its statement, ABI Research highlighted a smart city project in Holyoke, Massachusetts. Since February 2011, the city has been working with Cisco Systems to transform the former mill town into a smart and connected community within the year. The networking vendor plans to use technology to deliver urban services to generate new economic opportunity, improve education and bolster population retention, it said.

Over in the Asia-Pacific region, Songdo, a city in South Korea, was developed from the ground up to incorporate smart city concepts, a spokesperson told ZDNet Asia in an interview in June. The project is expected to be fully complete in 2020.